Historically, the convention was the final determinant of the nomination, and often contentious as various factions of party insiders maneuvered to advance their candidates. Since the almost universal adoption of the primary election for selecting delegates in the last quarter of the 20th century, however, the convention's significance has diminished. The national party focuses on the convention as a unity point to bring together a party platform and state parties by having delegates vote on issues, which the nominee can then incorporate into their presidential campaign.

In 2004 the convention drew some controversy when over 1800 individuals were arrested by the authorities, a record for a political convention in the U.S.[1] However 90% of those charges were eventually dropped.[1]

Three district delegates for each member of the United States House of Representatives from each state, sixteen from D.C., twenty from Puerto Rico, and six each from American Samoa, Guam, the Northern Mariana Islands, and the U.S. Virgin Islands.

From each state having cast at least a majority of its Electoral College votes for the Republican nominee in the preceding presidential election, four and one-half delegates at large plus a number of the delegates at large equal to 60 percent of the number of electoral votes of that state, rounding any fraction upwards.

One additional delegate at large to each state for any and each of the following public officials who is a member of the Republican Party elected in the year of the last preceding presidential election or at any subsequent election held prior to January 1 of the year in which the next national convention is held (this provision rewards those states where the state "Grand Old Party" (GOP) has been successful in electing candidates):

A majority of members of any chamber of the state legislature, if also presided over by a Republican

A majority of members of all chambers of the state legislature, if also presided over by a Republican

Any and each Republican United States Senator elected by such state in the six-year period prior to January 1 of the year in which the next national convention is held.

In addition, if the District of Columbia shall have cast its electoral votes, or a majority thereof, for the Republican nominee for President of the United States in the last preceding presidential election, it shall be permitted four and one half delegates at large plus the number of delegates at large equal to thirty percent (30%) of the 16 delegates at large allotted to the District of Columbia, rounding any fraction upward.

One alternate delegate is also awarded for each regular delegate except for members of the Republican National Committee.

The composition of the individual state and territory delegations is determined by the bylaws of their respective state and territory parties. Since 1972, almost all have appointed delegates by primary election results, although some, notably Iowa, use caucuses, and others combine the primary with caucuses or with delegates elected at a state convention.

In the past, competing factions of a state party sometimes drew up separate lists of delegates, each claiming to be the official one. One of the first agenda items at a convention is therefore credentialing, whereby the Credentials Committee determines which group is recognized as the official delegation.

Texas is the second-most populous state and a GOP stronghold. Its delegation would consist of 155 members, as follows:

Texas is allowed 10 delegates under the at-large rule.

The chairperson of the Texas GOP, the state national committeeman, and the state national committeewoman each count as one delegate, for a total of three delegates.

Texas has 36 members in the House of Representatives; thus, Texas is allowed 108 delegates (36 * 3) under the House membership rule.

As Mitt Romney carried Texas in the 2012 United States Presidential Election, and as Texas has 38 electors (36 House members plus its two Senators), Texas is allowed 4.5 delegates under the at-large provision plus an additional 22.8 delegates (38 * 60%), for a total of 27.3 (4.5 + 22.8), rounded upward to 28 delegates.

Of the 32 current members of the House, 20 are Republicans; thus, one additional delegate under this provision.

As both houses of the Texas Legislature are controlled by the GOP (98-52 in the Texas House of Representatives and 20-11 in the Texas Senate) and both chambers are presided over by a Republican (Joe Straus as the Speaker of the House and Dan Patrick as Lieutenant Governor, which presides over the Senate), two additional delegates (one for having any chamber meeting the criteria, and one additional for having both chambers meet the criteria).

As both United States Senators from Texas are Republicans (John Cornyn and Ted Cruz), and as both have been elected within the past six years, two additional delegates.

California is the most-populous state, but is a Democratic Party stronghold.

The delegation for California would get ten delegates at large, three for the state chair and members of the national committee, and 159 for its 53 seats in the U.S. House, but would not meet any of the other criteria, as the state did not vote for Romney, did not elect a Republican governor in the previous four years or a Republican United States Senator in the previous six years, and did not elect a majority of Republicans to its congressional delegation or either house of its legislature. It would therefore consist of 172 delegates, 11% more than those from Texas.

The delegation from Wyoming, the least-populous state, would get ten delegates at large, three for the state chair and members of the national committee, three for its one seat in the U.S. House, 6 because it voted for Romney (4.5 + .6, rounded up), one for electing a governor, two for electing a Member of Congress, two for electing a majority of both houses of the state legislature, and two for electing both United States Senators. Thus it would receive 29 delegates, equivalent to 18.7% of the Texas delegation, even though the Census estimate of the 2012 population of Wyoming (576,412), is only 2.21% of that for Texas (26,059,203).

Comparing the three states in terms of population, California gets one delegate for every 221,171 residents, Texas gets one for every 168,124, and Wyoming gets one for every 19,876.

The first Republican National Convention was held at Lafayette Hall in Pittsburgh on February 22–February 23, 1856. At this convention, the Republican Party was formally organized on a national basis, and the first Republican National Committee was elected. The first Republican National Convention to nominate a presidential candidate convened from June 17–-June 19, 1856 at the Musical Fund Hall in Philadelphia.

The 1924 Republican convention made history by being the first GOP convention to give women equal representation. The Republican National Committee approved a rule providing for a national committee-man and a national committee-woman from each state. Incumbent President Calvin Coolidge was formally nominated and went on to win the general election. The convention nominated Illinois Governor Frank Lowden for Vice President on the second ballot, but he declined the nomination. This is the only time a nominee refused to accept a vice-presidential nomination, forcing the nomination of someone else, an action that would be unthinkable in years to come.

At the 1972 convention, First Lady Pat Nixon became the first First Lady since Eleanor Roosevelt and the first Republican First Lady to deliver an address to the convention delegates.[3] It is now common practice for the presidential candidate's spouse to deliver an address to the delegates.

The 1996 convention at the San Diego Convention Center remains the last Republican Convention to be held in a convention center complex; all others since then have been held at sports stadiums or arenas.

Political advocates outside of the major parties have complained that both the Democratic and Republican conventions have violated their First Amendment rights to demonstrate, protest and advocate their ideas.[4] Both conventions have restricted protesters to demonstrating in "free speech zones" of fenced-in areas, sometimes surrounded by barbed wire, and not accessible to the delegates. Civil rights lawyers have complained that police indiscriminately arrest demonstrators and charge them with crimes even though they are not breaking the law. In New York 2004, police arrested people and testified under oath that the arrestees had been committing violent acts. Videotapes by bystanders and the New York City police themselves later contradicted that testimony, and showed that at least some arrestees had not been violent.[5] The City has settled lawsuits for false arrest. In 2008, St. Paul required the RNC to buy liability insurance to cover the police for legal fees and judgments arising from legal complaints by protesters.[6] Currently, protest groups organizing against the 2012 RNC, such as resistRNC, believe special security event ordinances escalate and even create the violence it claims to prevent.[7]